Crop Response to Soil Acidity Factors in Ultisols and Oxisols in Puerto Rico. VI. Grain Sorghum

Abstract

The effects of various soil acidity factors on yield and foliar composition of sorghum (Sorghum bicolor (L.) Moench) were determined. Sorghum responded strongly to liming in yield on two Ultisols and one Oxisol. The response was stronger on the Ultisols than on the Oxisol. On the Ultisols, yields of grain produced by a seed and a ratoon crop decreased as the percent Al saturation of the soil increased, averaging only 861 kg/ha on the Corozal clay, and only 428 kg/ha on the Corozal subsoil at the highest Al saturation percentage, as compared to 5,255 and 3,969 kg/ha with no Al, respectively. On the Oxisol, the yields were not so drastically reduced because the highest Al saturation attained was only 34%. On all soils, yields increased with increasing pH, and decreased as the Al/base ratio increased. The P content of the leaves decreased significantly with increasing soil acidity and was highly correlated with grain yields of the seed crop on the Ultisols. The Ca content of the leaves was not correlated with soil acidity factors, nor was it correlated as closely with yields as has been shown in crops such as soybean and corn.